Interaction of hepatitis c virus nonstructural protein 5A with core protein is critical for the production of infectious virus particles
Interaction of hepatitis c virus nonstructural protein 5A with core protein is critical for the production of infectious virus particles
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DOI：
10.1128/jvi.00826-08
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发表时间：
2008-08-01
影响因子：
5.4
通讯作者：
Suzuki, Tetsuro
中科院分区：
文献类型：
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作者：
Masaki, Takahiro;Suzuki, Ryosuke;Suzuki, Tetsuro
丙型肝炎病毒（HCV）的非结构蛋白5A（NS 5A）在RNA复制、干扰素抗性和病毒致病中具有多种多样的功能。最近的研究表明，NS 5A参与了感染性病毒颗粒的组装和成熟;然而，NS 5A如何参与病毒生产尚未完全阐明。在本研究中，我们证明NS 5A是HCV颗粒生产的先决条件，因为它与病毒衣壳蛋白（核心蛋白）的相互作用。病毒生产效率与NS 5A和核心蛋白之间的相互作用水平密切相关。丙氨酸取代NS 5A结构域III（氨基酸2428，2430和2433）中的C-末端丝氨酸簇损害NS 5A基础磷酸化，导致NS 5A-核心相互作用的显着减少，NS 5A的亚细胞定位的干扰，和破坏病毒粒子的生产。用谷氨酸替代相同的丝氨酸簇，其模拟磷酸丝氨酸的存在，部分保留了NS 5A-核心相互作用和病毒体产生，表明这些丝氨酸残基的磷酸化对于病毒体产生是重要的。此外，我们发现丝氨酸簇中的丙氨酸取代抑制了核心蛋白与病毒基因组RNA的结合，可能导致核衣壳组装的抑制。这些结果表明，NS 5A通过与核心蛋白相互作用在调节HCV颗粒形成的早期阶段中起着关键作用，并且其C-末端丝氨酸簇是NS 5A-核心相互作用的决定因素。
Nonstructurall protein 5A (NS5A) of the hepatitis C virus (HCV) possesses multiple and diverse functions in RNA replication, interferon resistance, and viral pathogenesis. Recent studies suggest that NS5A is involved in the assembly and maturation of infectious viral particles; however, precisely how NS5A participates in virus production has not been fully elucidated. In the present study, we demonstrate that NS5A is a prerequisite for HCV particle production as a result of its interaction with the viral capsid protein (core protein). The efficiency of virus production correlated well with the levels of interaction between NS5A and the core protein. Alanine substitutions for the C-terminal serine cluster in domain III of NS5A (amino acids 2428, 2430, and 2433) impaired NS5A basal phosphorylation, leading to a marked decrease in NS5A-core interaction, disturbance of the subcellular localization of NS5A, and disruption of virion production. Replacing the same serine cluster with glutamic acid, which mimics the presence of phosphoserines, partially preserved the NS5A-core interaction and virion production, suggesting that phosphorylation of these serine residues is important for virion production. In addition, we found that the alanine substitutions in the serine cluster suppressed the association of the core protein with viral genome RNA, possibly resulting in the inhibition of nucleocapsid assembly. These results suggest that NS5A plays a key role in regulating the early phase of HCV particle formation by interacting with core protein and that its C-terminal serine cluster is a determinant of the NS5A-core interaction.